GB2162554A - Oil palm fibre and rubberised oil palm fibre, process for their production and articles made therefrom - Google Patents

Abstract

The present invention provides a process for producing oil palm fibre from an oil palm tree bunch, comprising the steps of: (a) cutting the bunch longitudinally into small pieces; (b) opening the small pieces to provide a loose mass of fibrous material; and (c) separating said fibrous material from other materials associated with the bunch to produce said oil palm fibre. The oil palm fibre is then preferably treated with a latex mixture which is then cured to produce rubberised oil palm fibre. The oil palm fibre or rubberised oil palm fibre may be formed into articles such as automobile seats, furniture cushions and mattresses having good properties due to the lightness, resilience and durability of the oil palm fibre. <IMAGE>

Description

SPECIFICATION Oil palm fibre and rubberised oil palm fibre, processes for their production, and articles made therefrom The present invention relates to a process for the production of oil palm fibre, articles including said oil palm fibre and processes for the production of said articles.

Oil palm trees are grown in many equatorial and sub-equatorial countries. The trees have towards their tops bunches on which the fruit grow. At harvest time, the bunches bearing the fruit are cut off and collected for processing. The bunches are steamed for about 30 minutes at 1 20 C to 1 500C to loosen the fruit, which is then separated from the bunch in known manner.

The fruit is put to well known uses, for instance as a food or as a source of oil. However, hitherto, no large scale use for the bunches has been found.

It is therefore an aim of the present invention to provide a process whereby a useful product can be derived from palm oil tree bunches, and also to provide useful articles incorporating said product.

According to the present invention, there is provided a process for producing oil palm fibre from an oil palm tree bunch, comprising the steps of: (a) cutting the bunch longitudinally into small pieces; (b) opening the small pieces to provide a loose mass of fibrous material; and (c) separating said fibrous material from other materials associated with the bunch to produce said oil palm fibre.

It has been found necessary to cut the bunch longitudinally in order to ensure as far as possible that the length and strength of the fibre is retained. If the bunch is cut transversely, the fibre length and strength is substantially reduced.

The cutting step (a) may be carried out manually for instance using a band saw or a circular saw on a saw table. Alternatively, the bunch may be cut using automated machinery.

The opening step (b) may be carried out using a two section opener machine. In each section there is provided a shaft on which are mounted a number of independently rotatable propellors (rakes). The first section feeds material to the second section. In each section the cut pieces of the bunch are opened to produce a loose mass of fibre. However, any other machine may be used to open the pieces of the bunch. In this step the tightly packed fibres in the cut pieces are separated to a certain extent from, but still remain entangled with, one another.

The separating step (c) may be carried out in the opener machine, for instance by providing the bottom of the second section with a number of perforations or slots. Any non-entangled material, such as fruit not removed from the bunch, dust and debris, will fall through the perforations, leaving the loose fibrous mass in the opener machine.

Alternatively or additionally, the separating step may be carried out in a separate screening machine, such as a rotating conical screen.

As a result of the steaming process carried out to separate the fruit from the bunch, the oil palm fibre produced by the process of the present invention may have a significant water content. It is therefore preferable that the oil palm fibre be dried, for instance in a drying oven after the separation step.

Suitable drying conditions are a temperature of about 1200Cfor30to45 minutes.

The drying operation may produce more dust or may release more debris from the oil palm fibre, in which case the dried oil palm fibre may be subjected to a further separating step, for instance by returning it to the conical screen, in order to produce acceptably clean oil palm fibre.

The oil palm fibre thus produced is a dry loose fibrous mass, which may be used in this condition to produce, for instance, cushions for automobiles.

However, in this condition, the oil palm fibre is not suitable for packaging or transportation. Therefore, advantageously, the loose mass of fibre is somewhat compacted to form bales for transport.

Alternatively the loose mass of fibre may be twisted to form ropes which in turn are formed into coils for transport. Preferably the twisted ropes are stored for some tie (at least a week) to allow the fibres to curl, thus producing a more resilient fibre with better cushioning properties. The baling and rope-forming operations are weil known for such fibrous materials and therefore need no further description.

The oil palm fibre manufactured by the process of the present invention is light, resilient, hygenic and durable. Its characteristics make it suitable for use in providing, for instance, automobile seats since it can provide the required balance of hardness and resilience. The oil palm fibre may also be moulded into many shapes. The oil palm fibre may be used to pack goods for transport, such as precision instruments and electrical goods. It may also be used to produce furniture cushions, mattresses, carpet underlays and filters.

The present invention also includes as an article of commerce oil palm fibre.

In a preferred process for using the oil palm fibre made by the above process, the oil palm fibre is treated with a latex mixture which is then cured to produce rubberised oil palm fibre, which may be in the form of or formed into an article.

The rubberised article is preferably produced from twisted and curled ropes of the oil palm fibre in the following manner.

The rope is opened in a conventional rope opening machine, such as a Multimate Machine, which opens up the twisted fibre. The twisted fibre is then woven into a loose mat. If necessary, the opened ropes are passed through a separator for removing any dust or debris produced during the opening operation.

The opened ropes, which comprise a number of loosely entangled fibre ropes, and then intertwined in a carding machine to produce fibre sheets. The density, thickness and width of the sheets may be varied to suit the final use to which the oil palm fibre is to be put.

A latex mixture is then sprayed onto the fibre sheets and the sprayed sheets may be partially dried. At this stage the sheets may be cut into suitably shaped pieces and placed in a mould. The surface of each sheet as it is placed in the mould may be sprayed with further latex mixture to ensure that the pieces adhere together.

The shaped pieces are set into the mould and may, if desired, be pre-cured, for approximately one minute to assist the material to maintain its shape as moulded, after which any excess material may be removed.

The material is then cured fully by heating at 12000 to 1 50 C for one to four hours.

If desired, a finishing layer of polyurethane foam may be applied to the outer surfaces of the moulded article. This may be desirable where the moulded article is to be used as an automobile seat or a piece of furniture.

The present invention also includes rubberised oil palm fibre.

Any suitable latex may be used, and many examples of such latexes are known in the art. The latex may include, as necessary or desired, pigments, processing aids, stabilizers and other conventionally used additives.

Automobile cushions made from rubberised oil palm fibre have very good cushioning properties, with no bottoming out, are light in weight and do not require internal or external springing. Moreover, they are sufficiently hard to support correctly the passenger or driver in the seat.

One embodiment of the present invention is now described, by way of example only, with reference to the accompanying drawing, which shows schematically a process for producing an automobile seat including oil palm fibre.

Referring now to the drawing, harvested oil palm bunches having thereon fruit are fed to a steamer 1, wherein they are steamed for about 30 minutes at a temperature of 120 to 1 50"C to loosen the fruit from the bunch.

The steamed bunches are fed to a separator 3 comprising a rotatable shaft having on it a number of propellors. As the shaft is rotated the propellors separate the fruit from the bunch. The fruit falls through a perforated floor in the separator 3 and are collected. The stripped bunches are fed to the next stage in the process, wherein they are cut longitudinally into small pieces by cutter 5. In a preferred embodiment, the cutter 5 is a circular saw on a saw table and the bunches are cut manually. It is necessary to ensure that the bunches are cut longitudinally in orderto ensure as far as possible that fibre length and strength is retained.

The cut pieces are fed to an opener 7 which comprises a first section 7a leading to a second section 7b. A shaft is located in each section and each shaft has mounted thereon a number of independently rotatable propellors (rakes). As the propellors (rakes) are rotated the pieces of the bunches are opened to form a loose mass of fibre.

The bottom of the second section 7b is perforated and so much of the debris or dust formed during the opening process or associated with the pieces of the bunches and any fruit which was not separated from the bunch will fall through the perforated bottom and therefore be separated from the fibrous mass.

However, it is unlikely that all the dust, debris or unseparated fruit will fall through the perforated bottom, and therefore the fibrous mass is passed through a rotating conical screen 9. This comprises a perforated metal sheet which has been formed into a truncated cone. The cone is rotated at a constant rate by a motor (not shown) and therefore causes the fibrous mass to be tumbled during its passage through the screen 9. Dust, debris and unseparated fruit will pass through the screen 9.

Due to the original steaming step to loosen the fruit on the bunch, the loose fibrous mass will be somewhat wet, and it is therefore fed to a drier 11 wherein it is dried at 10000 for 30 to 45 minutes. It will occasionally be found that the dried fibrous mass is not sufficiently clean for further use, and in such cases the dried fibrous mass may be fed back to the screen 9 for further cleaning.

The product of the process so far, if necessary after the second cleaning step, is dried oil palm fibre comprising a loose mass of entangled fibres. It may be used in this state, for instance to provide stuffing for cushions, mattresses, or items of furniture or as a packaging material for precision machinery or electrical equipment. The oil palm fibre may also be used as a carpet underlay or in filters.

However, the oil palm fibre in this form is very bulky and difficult to transport in large weight quantities. Therefore, preferably the dried fibrous mass is passed through a twisting machine 12 wherein the fibres are twisted into ropes. Such machines are known in the art and therefore need no further explanation. The twisted ropes are then formed by a coiler 14 into coils weighing 25 to 28 kg and are stored in this condition for at least 30 days.

After this storage period the fibres are not only twisted but have also become curled. This improves the tensile and resilient properties of the fibre, which is of advantage in some of the applications of the oil palm fibre as described below.

In the coiled rope form, the oil palm fibre is easily transported in large weight quantities, and it is also in a form which can be readily processed into a useful article, such as an automobile seat, as described below.

The coils of twisted ropes of oil palm fibre are fed to a conventional rope, opening machine 15 wherein the twisted fibres are to a certain extent separated from one another. The twisted fibre is then woven into a loose fibrous mat. Atthis stage, the mat may be further cleaned by passing it through a cyclone separator (not shown).

The fibrous mat is then passed through a carding machine 17 wherein it is formed into fibre sheets.

The density, thickness and width of the sheets is variable by varying the operating parameters of the carding machine in accordance with the desired properties of the final product.

The fibre sheets are passed through a sprayer 19 which coats them with an aqueous rubber latex mixture of the following composition.

Latex (60% rubber solids, 40% water) 64%

Sulphur 2.34% Zinc Oxide 1.97% Vulcafor ZDC 0.294% Vulkacite ZM 0.15% Additives zit Vulknox CX 0.16% 6% kOH 0.09% Ag Gum 0.20% Dispersing agent 0.04% Latex Casin 0.023% Titanium dioxide 0.294% Water Water 5.8% 30% The coated sheets are then pre-cured by partially drying the mixture in a pre-curing oven 20 at 120"C for 3 minutes. This enables the sheets to retain their shape during subsequent processing steps.

The pre-cured sheets are cut into predetermined shapes and are inserted into a mould 21 in a predetermined order. As each shaped piece of sheet is inserted into the mould its exposed surface is sprayed with a further amount of the latex mixture to ensure that adjacent sheets adhere to one another. The mould 21 is shaped to form an automobile seat and the shaped pieces are designed so that the mould 21 is properly filled.

Once the mould 21 is properly filled, it is closed and the sheets are subjected to a preheating stage in preheating oven 22 at 12000 for about one minute to pre-cure the latex mixture. Thereafter, excess rubber is trimmed off the surfaces of the moulded article and the mould 21 containing the sheets is placed in an oven 23 at 120 to 15000four 1 to 4 hours to vulcanise completely the rubber mixture.

The vulcanised article is removed from the mould 21 and a layer of polyurethane foam is applied to the article in stage 25 to produce an acceptable finish thereon.

The automobile seat made by this process is resilient, but does not bottom out, and therefore does not need any mechanical springs. Moreover, it is sufficiently hard to provide a comfortable sitting position, and is extremely durable.

Alternatively, the coated sheets which have been pre-cured may be passed directly into the oven 23 wherein they are fully vulcanised at 120 to 15000 for 1 to 4 hours. The rubberised sheets thus produced will have good resilience, hardness and durability and can be used, for instance, to form articles of furniture, mattresses or cushions. In such cases it will be necessary to provide a suitable surface finish on the sheet to provide user acceptability.

It can thus be seen that the present invention provides a process which uses commercially for the first time oil palm bunches to produce a useful product (oil palm fibre). Moreover the oil palm fibre can itself be used to produce articles having unexpectedly and surprisingly good properties of resilience, durability and hardness. Moreover, as the oil palm fibre is a natural product, it will not present any health hazards to the users.

Claims (27)

1. A process for producing oil palm fibre from an oil palm tree bunch, comprising the steps of: (a) cutting the bunch longitudinally into small pieces; (b) opening the small pieces to provide a loose mass of fibrous material; and (c) separating said fibrous material from other materials associated with the bunch to produce said oil palm fibre.

2. The process of claim 1, in which the cutting step (a) is carried out manually with a band saw or a circular saw.

3. The process of claim 1 or claim 2, in which the opening step (b) is carried out using a two section opener machine, in each section of which is provided a shaft on which are mounted a number of independently rotatable propellors (rakes).

4. The process of claim 3, in which the opener has a perforated or slotted bottom in the second section through which debris falls to accomplish at least in part the separating step (c).

5. The process of any one of claims 1 to 4, in which the separating step (c) is carried out or completed by use of a separate screening machine.

6. The process of claim 5, wherein the screening machine comprises a rotating conical screen.

7. The process of any one of claims 1 to 6, further including the step of drying the oil palm fibre after the separating step.

8. The process of claim 7, including a further separating step carried out on the dried oil palm fibre.

9. The process of any one of claims 1 to 8 and including a further step of twisting the clean oil palm fibre into ropes.

10. The process of claim 9, and including a further step coiling the ropes.

11. A process for making oil palm fibre substantially as hereinbefore described with reference to the accompanying drawing.

12. Oil palm fibre. -

13. Oil palm fibre in the form of a dry loose fibrous mass.

14. Oil palm fibre in the form of a rope.

15. Oil palm fibre in the form of a coiled rope.

16. A process for producing rubberised oil palm fibre comprising treating oil palm fibre according to any one of claims 12 to 15 with a latex mixture which is then cured to produce the rubberised oil palm fibre.

17. The process of claim 16 wherein twisted and curled ropes of oil palm fibre are opened, woven into a loose mat, carded into sheets and sprayed with latex.

18. The process of claim 17, wherein the sprayed sheets are cut into shaped pieces and placed in a mould, and the latex is cured while the pieces are in the mould.

19. The process of claim 18, wherein the pieces are pre-cured and excess material is removed prior to the full curing of the latex.

20. The process of claim 18 or claim 19, wherein the pieces are sprayed with further latex as they are placed in the mould.

21. The process of any one of claims 16 to 19, wherein a finishing layer of polyurethane foam is applied to the outer surface of the rubberised oil palm fibre.

22. Rubberised oil palm fibre.

23. An automobile seat, packaging material, piece of furniture, furniture cushion, mattress, or carpet underlay comprising oil palm fibre or rubberised oil palm fibre as the cushioning material.

24. Oil palm fibre substantially as herein before defined with reference to the accompanying drawing.

25. A process for producing rubberised oil palm fibre substantially as hereinbefore defined with reference to the accompanying drawing.

26. Rubberised oil palm fibre substantially as hereinbefore defined with reference to the accompanying drawing.

27. An automobile seat comprising rubberised oil palm fibre substantially as hereinfefore defined with reference to the accompanying drawing.